The Plant Kingdom (Part I) Kingdom Characteristics Engage Doom’s Day Vault Video Explore Plant Kingdom Lab Explain Multicellular, Eukaryotic, AutotrophicPhotosynthetic Plant Cells 1. 2. 3. 4. Cell walls of cellulose Chloroplasts Large central vacuole Cuticle: waxy waterproof coating Plant Origin First plants 1. 2. 3. 500 mya Looked like mosses Probably evolved from green algae Cellulose cell walls Same type of chlorophyll Store excess food as starch Evolution of Plants (Cladogram) Flowering plants Cone-bearing plants Ferns and their relatives Flowers; Seeds Enclosed in Fruit Mosses and their relatives Seeds Water-Conducting (Vascular) Tissue Green algae ancestor Adaptations of Plants to Land Seeds (Dormant until water added) Roots Stems Leaf – Autotrophic Organisms Must Conserve Water (Stomata) Reproductive Strategies Roots, Stems, and Leaves Plant Tissues Root, Stem, and Leaf Tissues Leaf Stem Root Dermal tissue Vascular tissue Ground tissue Section 23-1 Plant Tissues include Dermal tissue Meristematic tissue includes Epidermal cells includes Xylem includes Tracheids Vascular tissue Vessel elements Ground tissue includes Phloem Parenchyma cells includes Sieve tube elements Companion cells Collenchyma cells Schlerenchyma cells 1. The Seed External Structures 1. Seed coat 2. Hilum 3. Micropyle Internal Structures 1. Embryo plant 2. Cotyledon Germination – To Begin to Grow 2. Roots: Anchors Away Functions Anchors the plant Absorbs water and minerals from soil Stores food Primary Root The first root to develop from the seed. Secondary Roots Develop from the primary root and from themselves. Tap Root System Develops from the primary root. Reaches deep into the ground Helps the plant during periods of drought. Fibrous Root System Develops when the secondary roots become the main roots. Shallow roots but spread over a broad area. Helps prevent erosion. Epidermis Endodermis Root hairs Ground tissue (cortex) Phloem Xylem Vascular Cylinder Ground tissue (cortex) Epidermis Endodermis Vascular cylinder Zone of maturation Zone of elongation Apical meristem Cross Section of Plant Root Root cap (magnification: 40x) The Root Tip Root cap (Protects the root from abrasion) Apical Meristem (Produces new cells for growth) Zone of Elongation (Cells elongate allowing the root to grow longer) Zone of Maturation (Cells develop into tissues) 3. Stems: The Connector Functions Connects the leaves with the roots Displays the leaves for maximum sunlight exposure. Stores food Minor photosynthetic ability Contains vascular tissue Phloem – transports sugars from leaves Xylem – transports water and minerals from roots Comparing Primary and Secondary Growth of Stems Characteristics Primary Growth Secondary Growth Where It Occurs At ends of plants In stem Effect on Plant Increases plant length Increases stem width How It Is Produced By cell division in the apical meristem By cell division in meristems other than the apical meristem Secondary Growth in Stems A. Vascular cambium appears Cork cambium Cortex Vascular cambium Pith Primary phloem Secondary xylem Wood Primary xylem Secondary phloem Primary xylem C. Mature stem develops Secondary Bark phloem Cork Epidermis Primary phloem B. Secondary growth continues Secondary xylem Layers of a Tree Trunk Wood Bark Cork Contains old, nonfunctioning phloem that protects the tree Xylem: Heartwood Contains old, nonfunctioning xylem that helps support the tree Cork Cambium Produces protective layer of cork Phloem Transports sugars produced by photosynthesis Xylem: Sapwood Contains active xylem that transports water and minerals Vascular Cambium Produces new xylem and phloem, which increase the width of the stem 4. Leaf - Autotrophic Functions Carries on Photosynthesis Stores food Regulates transpiration through stomata Internal Structure of a Leaf Section 23-4 Cuticle Veins Epidermis Palisade mesophyll Xylem Vein Phloem Spongy mesophyll Epidermis Stoma Guard cells Internal Leaf Anatomy Cuticle Epidermis Palisade Mesophyll (chloroplasts) Spongy Mesophyll Vein (xylem and phloem) Air Spaces Lower Epidermis Stomata Guard cells Sugar Transport in Phloem Nutrient Transport Occurs in PHLOEM Pressure-flow hypothesis 5. Water Conservation Cuticle Waxy outer coating that prevents water loss Stomata Openings for gas exchange Open to release water, Close to conserve Stomata Stomata Guard cells regulate the size of the stoma. K+ (potassium ions) enter the cells causing them to fill with water. This opens the stoma when they become turgid. A loss of K+ causes the opposite to occur, and they close when they become flaccid. Section 23-4 Guard cells Guard cells Inner cell wall Inner cell wall Stoma Stoma Open Stoma Closed Section 23-4 Guard cells Guard cells Inner cell wall Inner cell wall Stoma Stoma Open Stoma Closed Transpiration Water Transport 1. 2. Root Pressure Capillary Action 3. Adhesion – attraction between unlike Cohesion – attraction between like Transpirational Pull Pulling water up through the vascular tissue due to evaporation and capillary action 6. Reproductive Strategies 1. Seeds 2. Contains an embryo Contains a food supply Covered by a protective coat Spores Single haploid cell with hard outer wall Elaborate Xylem Demonstration The Magic Toothpick Linking Up Demonstration Stomata Lab Transpiration Lab Evaluate